I recently had to remove the exhaust manufold to drill and tap a new hole from a broken bolt. The manufold is "slotted" where the bolts attach. This is not from wear but actual make. How do you get the intake and exhaust holes in the block to align with the holes in the manufold ? There is a movement of over one half inch +/-. I guessed and hope for good results...but there must be a certain method of alignment.